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参数资料
| 型号： | TPS62238DRY |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 稳压器 |
| 英文描述： | 1.22 A SWITCHING REGULATOR, 3800 kHz SWITCHING FREQ-MAX, PDSO6 |
| 封装： | 1 X 1.50 MM, 0.60 MM HEIGHT, PLASTIC, MO-287UFAD, SON-6 |
| 文件页数： | 13/32页 |
| 文件大小： | 1073K |
| 代理商： | TPS62238DRY |
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OUT
ONmin
IN
V
t
=
260 ns
V
IN
OUT
LPFMpeak
ONmin
(V
V
)
I
=
t
L
-
(
)
IN
OUT
DS(on)
L
V min = V
max + I
max
R
max+ R
TPS62231, TPS62230, TPS62232, TPS62233, TPS62234, TPS62235
TPS62236, TPS62237, TPS62238, TPS62239, TPS622310, TPS622311
TPS622312, TPS622313, TPS622314, TPS622315, TPS622316, TPS622317
SLVS941D – APRIL 2009 – REVISED AUGUST 2010
www.ti.com
In PFM Mode, the device starts to skip switch pulses and generates only single pulses with an on time of tONmin.
The PFM Mode frequency depends on the load current and the external inductor and output capacitor values.
The PFM Mode of TPS6223X is optimized for low output voltage ripple if small external components are used.
Even at low output currents, the PFM frequency is above the audible noise spectrum and makes this operation
mode suitable for audio applications.
The on time tONmin can be estimated to:
(1)
Therefore, the peak inductor current in PFM mode is approximately:
(2)
With
tON: High side switch on time [ns]
VIN: Input voltage [V]
VOUT: Output voltage [V]
L : Inductance [mH]
ILPFMpeak : PFM inductor peak current [mA]
FORCED PWM MODE
Pulling the MODE pin high forces the converter to operate in a continuous conduction PWM mode even at light
load currents. The advantage is that the converter operates with a quasi fixed frequency that allows simple
filtering of the switching frequency for noise-sensitive applications. In this mode, the efficiency is lower compared
to the power-save mode during light loads.
For additional flexibility, it is possible to switch from power-save mode to forced PWM mode during operation.
This allows efficient power management by adjusting the operation of the converter to the specific system
requirements.
100% DUTY CYCLE LOW DROPOUT OPERATION
The device starts to enter 100% duty cycle mode once the input voltage comes close to the nominal output
voltage. In order to maintain the output voltage, the High Side switch is turned on 100% for one or more cycles.
With further decreasing VIN the High Side MOSFET switch is turned on completely. In this case the converter
offers a low input-to-output voltage difference. This is particularly useful in battery-powered applications to
achieve longest operation time by taking full advantage of the whole battery voltage range.
The minimum input voltage to maintain regulation depends on the load current and output voltage, and can be
calculated as:
(3)
With:
IOUTmax = maximum output current plus inductor ripple current
RDS(on)max = maximum P-channel switch RDSon.
RL = DC resistance of the inductor
VOUTmax = nominal output voltage plus maximum output voltage tolerance
UNDER VOLTAGE LOCKOUT
The under voltage lockout circuit prevents the device from misoperation at low input voltages. It prevents the
converter from turning on the switch or rectifier MOSFET under undefined conditions. The TPS6223X devices
have a UVLO threshold set to 1.8V (typical). Fully functional operation is permitted for input voltage down to the
falling UVLO threshold level. The converter starts operation again once the input voltage trips the rising UVLO
threshold level.
20
Copyright 2009–2010, Texas Instruments Incorporated
相关PDF资料 |
PDF描述 |
|---|---|
| TPS622315DRYT | 1.22 A SWITCHING REGULATOR, 3800 kHz SWITCHING FREQ-MAX, PDSO6 |
| TPS62236DRYR | 1.22 A SWITCHING REGULATOR, 3800 kHz SWITCHING FREQ-MAX, PDSO6 |
| TPS622310DRYT | 1.22 A SWITCHING REGULATOR, 3800 kHz SWITCHING FREQ-MAX, PDSO6 |
| TPS622313DRYR | 1.22 A SWITCHING REGULATOR, 3800 kHz SWITCHING FREQ-MAX, PDSO6 |
| TPS62235DRY | 1.22 A SWITCHING REGULATOR, 3800 kHz SWITCHING FREQ-MAX, PDSO6 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TPS62238DRYR | 功能描述:直流/直流开关转换器 3MHz 500mA Step- Down Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| TPS62238DRYT | 功能描述:直流/直流开关转换器 3MHz 500mA Step- Down Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| TPS62239DRYR | 功能描述:直流/直流开关转换器 3MHz 500mA Step- Down Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| TPS62239DRYT | 功能描述:直流/直流开关转换器 3MHz 500mA Step- Down Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| TPS62239EVM-574 | 功能描述:电源管理IC开发工具 TPS62239 Eval Mod RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
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